Factor out the template transformation of a sequence of function

parameters into parameter types, so that substitution of
explicitly-specified function template arguments uses the same
path. This enables the use of explicitly-specified function template
arguments with variadic templates.

llvm-svn: 122986
This commit is contained in:
Douglas Gregor 2011-01-07 00:20:55 +00:00
parent b13ee84c26
commit dd47216cc4
7 changed files with 115 additions and 40 deletions

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@ -1008,11 +1008,6 @@ class FunctionTypeLoc : public ConcreteTypeLoc<UnqualTypeLoc,
FunctionTypeLoc,
FunctionType,
FunctionLocInfo> {
// ParmVarDecls* are stored after Info, one for each argument.
ParmVarDecl **getParmArray() const {
return (ParmVarDecl**) getExtraLocalData();
}
public:
SourceLocation getLParenLoc() const {
return getLocalData()->LParenLoc;
@ -1035,6 +1030,11 @@ public:
getLocalData()->TrailingReturn = Trailing;
}
// ParmVarDecls* are stored after Info, one for each argument.
ParmVarDecl **getParmArray() const {
return (ParmVarDecl**) getExtraLocalData();
}
unsigned getNumArgs() const {
if (isa<FunctionNoProtoType>(getTypePtr()))
return 0;

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@ -3890,6 +3890,10 @@ public:
DeclarationName Entity);
ParmVarDecl *SubstParmVarDecl(ParmVarDecl *D,
const MultiLevelTemplateArgumentList &TemplateArgs);
bool SubstParmTypes(SourceLocation Loc,
ParmVarDecl **Params, unsigned NumParams,
const MultiLevelTemplateArgumentList &TemplateArgs,
llvm::SmallVectorImpl<QualType> &ParamTypes);
ExprResult SubstExpr(Expr *E,
const MultiLevelTemplateArgumentList &TemplateArgs);

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@ -1889,19 +1889,11 @@ Sema::SubstituteExplicitTemplateArguments(
// Instantiate the types of each of the function parameters given the
// explicitly-specified template arguments.
for (FunctionDecl::param_iterator P = Function->param_begin(),
PEnd = Function->param_end();
P != PEnd;
++P) {
QualType ParamType
= SubstType((*P)->getType(),
MultiLevelTemplateArgumentList(*ExplicitArgumentList),
(*P)->getLocation(), (*P)->getDeclName());
if (ParamType.isNull() || Trap.hasErrorOccurred())
return TDK_SubstitutionFailure;
ParamTypes.push_back(ParamType);
}
if (SubstParmTypes(Function->getLocation(),
Function->param_begin(), Function->getNumParams(),
MultiLevelTemplateArgumentList(*ExplicitArgumentList),
ParamTypes))
return TDK_SubstitutionFailure;
// If the caller wants a full function type back, instantiate the return
// type and form that function type.

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@ -1221,6 +1221,23 @@ ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
return NewParm;
}
/// \brief Substitute the given template arguments into the given set of
/// parameters, producing the set of parameter types that would be generated
/// from such a substitution.
bool Sema::SubstParmTypes(SourceLocation Loc,
ParmVarDecl **Params, unsigned NumParams,
const MultiLevelTemplateArgumentList &TemplateArgs,
llvm::SmallVectorImpl<QualType> &ParamTypes) {
assert(!ActiveTemplateInstantiations.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
DeclarationName());
return Instantiator.TransformFunctionTypeParams(Loc, Params, NumParams, 0,
ParamTypes, 0);
}
/// \brief Perform substitution on the base class specifiers of the
/// given class template specialization.
///

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@ -439,9 +439,11 @@ public:
/// variables vector are acceptable.
///
/// Return true on error.
bool TransformFunctionTypeParams(FunctionProtoTypeLoc TL,
bool TransformFunctionTypeParams(SourceLocation Loc,
ParmVarDecl **Params, unsigned NumParams,
const QualType *ParamTypes,
llvm::SmallVectorImpl<QualType> &PTypes,
llvm::SmallVectorImpl<ParmVarDecl*> &PVars);
llvm::SmallVectorImpl<ParmVarDecl*> *PVars);
/// \brief Transforms a single function-type parameter. Return null
/// on error.
@ -3390,13 +3392,13 @@ TreeTransform<Derived>::TransformFunctionTypeParam(ParmVarDecl *OldParm) {
template<typename Derived>
bool TreeTransform<Derived>::
TransformFunctionTypeParams(FunctionProtoTypeLoc TL,
llvm::SmallVectorImpl<QualType> &PTypes,
llvm::SmallVectorImpl<ParmVarDecl*> &PVars) {
FunctionProtoType *T = TL.getTypePtr();
for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i) {
if (ParmVarDecl *OldParm = TL.getArg(i)) {
TransformFunctionTypeParams(SourceLocation Loc,
ParmVarDecl **Params, unsigned NumParams,
const QualType *ParamTypes,
llvm::SmallVectorImpl<QualType> &OutParamTypes,
llvm::SmallVectorImpl<ParmVarDecl*> *PVars) {
for (unsigned i = 0; i != NumParams; ++i) {
if (ParmVarDecl *OldParm = Params[i]) {
if (OldParm->isParameterPack()) {
// We have a function parameter pack that may need to be expanded.
llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
@ -3428,8 +3430,9 @@ bool TreeTransform<Derived>::
if (!NewParm)
return true;
PTypes.push_back(NewParm->getType());
PVars.push_back(NewParm);
OutParamTypes.push_back(NewParm->getType());
if (PVars)
PVars->push_back(NewParm);
}
// We're done with the pack expansion.
@ -3445,14 +3448,15 @@ bool TreeTransform<Derived>::
if (!NewParm)
return true;
PTypes.push_back(NewParm->getType());
PVars.push_back(NewParm);
OutParamTypes.push_back(NewParm->getType());
if (PVars)
PVars->push_back(NewParm);
continue;
}
// Deal with the possibility that we don't have a parameter
// declaration for this parameter.
QualType OldType = T->getArgType(i);
QualType OldType = ParamTypes[i];
bool IsPackExpansion = false;
if (const PackExpansionType *Expansion
= dyn_cast<PackExpansionType>(OldType)) {
@ -3464,7 +3468,7 @@ bool TreeTransform<Derived>::
// Determine whether we should expand the parameter packs.
bool ShouldExpand = false;
unsigned NumExpansions = 0;
if (getDerived().TryExpandParameterPacks(TL.getBeginLoc(), SourceRange(),
if (getDerived().TryExpandParameterPacks(Loc, SourceRange(),
Unexpanded.data(),
Unexpanded.size(),
ShouldExpand, NumExpansions)) {
@ -3480,8 +3484,9 @@ bool TreeTransform<Derived>::
if (NewType.isNull())
return true;
PTypes.push_back(NewType);
PVars.push_back(0);
OutParamTypes.push_back(NewType);
if (PVars)
PVars->push_back(0);
}
// We're done with the pack expansion.
@ -3502,8 +3507,9 @@ bool TreeTransform<Derived>::
if (IsPackExpansion)
NewType = getSema().Context.getPackExpansionType(NewType);
PTypes.push_back(NewType);
PVars.push_back(0);
OutParamTypes.push_back(NewType);
if (PVars)
PVars->push_back(0);
}
return false;
@ -3530,7 +3536,11 @@ TreeTransform<Derived>::TransformFunctionProtoType(TypeLocBuilder &TLB,
QualType ResultType;
if (TL.getTrailingReturn()) {
if (getDerived().TransformFunctionTypeParams(TL, ParamTypes, ParamDecls))
if (getDerived().TransformFunctionTypeParams(TL.getBeginLoc(),
TL.getParmArray(),
TL.getNumArgs(),
TL.getTypePtr()->arg_type_begin(),
ParamTypes, &ParamDecls))
return QualType();
ResultType = getDerived().TransformType(TLB, TL.getResultLoc());
@ -3542,7 +3552,11 @@ TreeTransform<Derived>::TransformFunctionProtoType(TypeLocBuilder &TLB,
if (ResultType.isNull())
return QualType();
if (getDerived().TransformFunctionTypeParams(TL, ParamTypes, ParamDecls))
if (getDerived().TransformFunctionTypeParams(TL.getBeginLoc(),
TL.getParmArray(),
TL.getNumArgs(),
TL.getTypePtr()->arg_type_begin(),
ParamTypes, &ParamDecls))
return QualType();
}

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@ -0,0 +1,47 @@
// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s
// Metafunction to extract the Nth type from a set of types.
template<unsigned N, typename ...Types> struct get_nth_type;
template<unsigned N, typename Head, typename ...Tail>
struct get_nth_type<N, Head, Tail...> : get_nth_type<N-1, Tail...> { };
template<typename Head, typename ...Tail>
struct get_nth_type<0, Head, Tail...> {
typedef Head type;
};
// Placeholder type when get_nth_type fails.
struct no_type {};
template<unsigned N>
struct get_nth_type<N> {
typedef no_type type;
};
template<typename ...Args>
typename get_nth_type<0, Args...>::type first_arg(Args...);
template<typename ...Args>
typename get_nth_type<1, Args...>::type second_arg(Args...);
// Test explicit specification of function template arguments.
void test_explicit_spec_simple() {
int *ip1 = first_arg<int *>(0);
int *ip2 = first_arg<int *, float*>(0, 0);
float *fp1 = first_arg<float *, double*, int*>(0, 0, 0);
}
// Template argument deduction can extend the sequence of template
// arguments corresponding to a template parameter pack, even when the
// sequence contains explicitly specified template arguments.
// FIXME: Actually test what this paragraph specifies.
#if 0
void test_explicit_spec_extension() {
int *ip1 = first_arg<int *>(0, 0);
int *ip2 = first_arg<int *, float*>(0, 0, 0, 0);
float *fp1 = first_arg<float *, double*, int*>(0, 0, 0);
int i1 = second_arg<float *>(0, 0, 0);
}
#endif

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@ -169,7 +169,8 @@ namespace pr6249 {
}
namespace PR6723 {
template<unsigned char C> void f(int (&a)[C]); // expected-note 2{{candidate template ignored}}
template<unsigned char C> void f(int (&a)[C]); // expected-note {{candidate template ignored}} \
// expected-note{{candidate function [with C = 0] not viable: no known conversion from 'int [512]' to 'int (&)[0]' for 1st argument}}
void g() {
int arr512[512];
f(arr512); // expected-error{{no matching function for call}}